Diethylene glycol monoethyl ether (DGME) is 2-(2-ethoxyethoxy)ethanol (DEGEE) and is typically labelled in cosmetics under the INCI name “Ethoxydiglycol”.

It is a low-molecular-weight glycol ether (ether alcohol) selected mainly for broad-spectrum solvency: it is fully miscible with water yet provides useful organic solvency, helping keep multi-ingredient systems clear and single-phase.

Identity: CAS 111-90-0; EC 203-919-7; empirical formula C6H14O3; hygroscopic; reported log Pow around −0.5 (hydrophilic polarity profile).

Product Description: DGME/Ethoxydiglycol functions as a coupling solvent/co-solvent in cosmetic and topical formulations where solubility and distribution of actives materially affects clarity, stability, and delivery.

Useful information (technical):

- Solvent / co-solvent: bridges hydrophilic and moderately lipophilic ingredients to reduce haze, precipitation, or phase separation.

- Fragrance carrier: dissolves fragrance concentrates in non-alcoholic bases and supports “perfuming” systems.

- Viscosity reduction: thins the bulk to improve pumpability, filling, spray/roll-on flow, spreadability, and rub-out.

- Humectancy (secondary): hygroscopicity can contribute modestly to water retention, although solvency is usually the dominant role.

- Dermal delivery support: can increase the dissolved fraction of an active and improve partitioning into the stratum corneum; this may improve performance but can also increase irritation potential for strong actives (formula-dependent).

Common cosmetic product types:

- Hair dyes (oxidative and non-oxidative): solvent for dyes/precursors and application aid.

- Rinse-off products (cleansers, shampoos, washes): solvent/solubiliser for actives and fragrance.

- Leave-on, non-spray products (lotions, creams, serums): solvency and delivery performance for dissolved actives.

- Spray products (fine fragrance, hair sprays, antiperspirants/deodorants): solvent/carrier where applicable.

Regulatory & specification notes (EU):

- Restricted by product type under EU Cosmetics Regulation Annex III (Commission Regulation (EU) 2016/314).

- Maximum concentration in ready-for-use products: 7% (oxidative hair dyes), 5% (non-oxidative hair dyes), 10% (rinse-off other than hair dyes), 2.6% (other non-spray products), 2.6% (specified spray products: fine fragrances, hair sprays, antiperspirants, deodorants).

- Ethylene glycol impurity must be controlled to ≤ 0.1%; not to be used in eye products or oral products under this restriction entry.

Usage: Suitable as a solvent/co-solvent or fragrance/active carrier in rinse-off and leave-on cosmetics (including serums, lotions/creams, cleansers/shampoos, deodorants/antiperspirants, and hair dye systems). Always apply local regulatory limits for the intended product format.

Mixing method:

- Add to the water phase or to a solvent blend to pre-dissolve actives and/or fragrance components before combining with the main batch.

- In emulsions, incorporate into the phase where the target active is soluble; can also be used in cool-down when handling heat-sensitive actives.

- If used to enhance solubility/delivery of potent actives, start at the low end and adjust while monitoring clarity and skin feel; avoid eye-area/oral product formats where restricted.

Usage rate: 0.1–10%

Higher levels may be used as a dedicated solvent in special systems; follow the applicable regulatory concentration limits by product type (e.g., EU Annex III restrictions).

Product characteristics: Clear liquid

Solubility: Miscible with water and many polar solvents; useful for solubilising many moderately polar actives and fragrance materials in mixed systems.

Storage: Store tightly closed to minimize moisture uptake; keep away from heat and direct sunlight.